Improvement in telescopic sights for fire-arms



lJNrT D STATES PATE T FFICEO JOSEPH M. TROWBRIDGE, OF UNITED STATESARMY.

IMPROVEMENT IN TELESCOPIC SIGHTS FOR FlR E-ARMS.

Specification forming part of Letters Patent No. 4k ll.,74l, dated March8, 1864 To all whom it may concern:

Be it known that I, JosEPH M.TROWBRIDGE, of United States Army, haveinvented a new and useful Telescopic Sight for Fire- Arms; and I dohereby declare the following to be a full, clear, and exact descriptionthereof, reference' being had to the accompanying drawings, making partof this specification.

My invention has for its object, first, such arangement and applicationof the telescope to firearms as shall free it from liability toderangement or dislodgment by the ordinary accidents incident tomilitary and sporting uses; second, a provision for determiningapproximate distances and ranges for military purposes.

Figure 1 is a side view, representing a Ballard rifle mounted with mytelescopic sight. Fig. 2 is an enlarged transverse section through thediaphragm. Fig. 3 is an enlarged longitudinal section of that part ofthe sight near the diaphragm.

A is the stout tube of wrought-iron or steel, less than one-half thelength of an ordinary gun-barrel, and permanently affixed to the barrelby means of straps a a, or equivalent means, and extending in rear ofthe gun-bar- 'rel sufficiently to 'come naturally to the eye whenaiming. In the tube A is a diaphragm consisting of .an annulus, D,bearing one vertical and several horizontal cross-wires. Springs E E,reacting against set-screws F F, hold the diaphragm D to any position,horizontal or vertical, to which it may be adjusted by means of the saidscrews. Such adjustment, when once correctly made, will not require tobe disturbed, as the several horizontal wires, each marking a differentrange, afford all the changes of elevation required in use, and thelateral adjustment remains fixed. Thehorizontal wires also serve tomeasure distances in military engagements at long range.

The above described invention is adapted and intended to be used withordnance as well as with small-arms.

Being aware that telescopic sights have before been used consisting ofcrosswvires fixed in movable telescopes, the following is what I claimas new in my invention and desire to secure by Letters Patent:

l. A cross-line diaphragm mounted adj 11stably within a telescopeattached rigidly to a fire-arm, whereby the instrument is renderedsecure from derangement by ordinary military and sporting usage.

2. Securing the diaphragm D adjustably within the telescope A by springsE E, reacting against set-screws F F, substantially as and for thepurposes set forth.

In testimony of which invention I hereunto set my hand.

J. M. TROW'BRIDGE.

\Vitnesses:

G120. H. KNIGHT, CHARLES L. Frsrrnn.

